Heat-Fueled Thunderstorms to Slam Northern PA, SW NY with 70 MPH Gusts — SevereWX

Thunderstorms are firing up this afternoon across northern Pennsylvania into southwestern New York, driven by scorching surface temperatures already hitting the low 90s F.

These storms exceed the convective temperature from recent soundings, sparking development amid deepening cumulus fields visible on satellite. Expect coverage to expand soon, especially as boundary layer heats further.

The environment features steep lapse rates aloft and high LCLs, priming downdrafts for potent wind gusts of 55-70 mph. Though deep-layer shear is weak at 10-15 knots—favoring disorganized cells or loose clusters—high instability and modest moisture will fuel damaging outflows.

Ensemble models like the HREF, HRRR, and RRFS hint at multiple rounds initiating off the Great Lakes, with potential for bowing segments. Uncertainty in organization and coverage tempers watch confidence for now, but SPC rates issuance at 60%.

Peak gusts could reach 70 mph in the strongest storms through late afternoon (11:25 AM - 1:30 PM CDT valid period).

Stay prepared: Monitor radar and local alerts closely. Secure outdoor items, avoid flooded roads, and have a severe weather plan ready if a watch is issued.